Evaluating the heterogeneity of hippocampal avoidant whole brain radiotherapy treatment effect: A secondary analysis of NRG CC001

Hua-Ren R Cherng, Kai Sun, Søren Bentzen, Terri S Armstrong, Vinai Gondi, Paul D Brown, Minesh Mehta, Mark V Mishra

Research output: Contribution to journalArticlepeer-review

Abstract

BACKGROUND: Hippocampal avoidant whole brain radiotherapy (HA-WBRT) is the standard of care for patients needing WBRT for brain metastases. This study, using existing data from NRG Oncology CC001 including baseline tumor characteristics and patient-reported MD Anderson Symptom Inventory-Brain Tumor (MDASI-BT) scores, sought to identify subgroups of patients that demonstrate differential neuroprotective treatment response to HA-WBRT.

METHODS: An exploratory analysis of NRG CC001, a phase 3 trial in which 518 patients were randomly assigned to WBRT plus memantine or HA-WBRT plus memantine, was performed. Rates of neurocognitive function failure (NCFF) were estimated between subgroups and stratified by arm. Covariate and subgroup interaction with differential treatment response were calculated.

RESULTS: The benefit of HA-WBRT on decreasing NCFF was seen in patients living ≥ 4 months (HR 0.75, 95% CI: 0.58-0.97, P = .03), whereas patients living < 4 months derived no significant neurocognitive benefit. A significant association between baseline MDASI-BT cognitive factor and treatment response (interaction P = .03) was identified. Patients with lower MDASI-BT scores (less patient-reported cognitive impairment) derived significantly greater benefit (HR = 0.64, 95% CI: 0.48-0.85, P = .002) compared to those with highest MDASI-BT scores (HR = 1.24, 95% CI: 0.76-2.04, P = .39). Tumor histology also had a significant interaction (P = .01) with treatment response. Primary lung histology patients derived cognitive failure risk reduction (HR = 0.58, 95% CI: 0.43-0.77, P = .0007) from HA-WBRT, in contrast to nonlung primary histology patients (HR = 1.15, 95% CI: 0.78-1.50, P = .48).

CONCLUSIONS: Differential neuroprotective response to HA-WBRT was identified in this analysis. Patients surviving ≥ 4 months derived benefit from HA-WBRT. There is evidence of heterogeneity of treatment effect for patients with less severe patient-reported cognitive impairment at baseline and those with primary lung histology.

Original languageEnglish
Pages (from-to)911-921
Number of pages11
JournalNeuro-Oncology
Volume26
Issue number5
DOIs
StatePublished - Apr 3 2024

Keywords

  • Humans
  • Brain Neoplasms/radiotherapy
  • Male
  • Female
  • Middle Aged
  • Hippocampus/pathology
  • Cranial Irradiation/methods
  • Aged
  • Memantine/therapeutic use
  • Adult
  • Follow-Up Studies
  • Prognosis

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